Wing or propeller for aerial dynamics and other purposes.



. R. W. SPRINGER.

WING 0R PROPELLEB FOR AERIAL DYNAMICS AND OTHER PURPOSES. APPLlcAloN msn,1116.11.1907. RENEWED ma. 29. i915.,

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renteenl Winnen: srniirrcnn, or' iiirii'icors.

ii/frire on :enornrrnri rer, finnish'nrniiirrcs.erin orner,

Be it known ther; l, Ecrire ZTiLLiAM- SPRINGER, a' citizen of thellnited .idiotes of America, residinget Springiield, in the' State of'illinois, United States of America,

have invented nen7 and .useiiul Wings or yPropellers for Aerial Dynamicsand other Purposes; and I do` hereby declare the fol lowing to be efull, cleer, `end exact description of the seme.

The'objeet of this invention is to provide e Wing' of improved shape foruse in `aerial dynamics, which Will .most eiiectuelly and economicallyntilizethe pressure ci the cir. This Wing may he used upon e soerincggxme chine, or upon :i motor-driven aeroplane, or for the Wings of enevieting, or flapping Wing machine. i

' It is important that terms shall he used in this description whichvwill have only one perfectly clearineening; hence the followl 4 ingdefinitions:

vfirs The dimension ci nf Wing in the direction of Hight is moreproperiy called its foreend-aft; and the dimension of the Wing at rightangles to the fore-and-eft isczilled its spread. The single of elevationor depres sion of the front edge of an aeroplane will be hereindesignated as its pitch., The term .Wing,79 especially es used in theclaims, is intended to be broader-dough so cover a `ixed aeroplane or anavieting aeroplane. j

have found 'that the roper curi/e for a Wing Will he the combination 'orequal 'forefand-eft increments with simpie' hurmonic motion. The curve,thus traced, is called a sinusoid. y

Reference is 'bo be had to the eccompany-k ing drawings, wherein Figurel is e diagram illustrating the manner of prodiiclng sinusoid curves, inVarious proportions, for the making of wings, Fig. 2 is e, longi tudinalverticol section, end Fig. 3 is e plein view of several superpcsedwings, illuszretl ing thefproportionsfoi.Wings for rapid and slow Hight.f- I lIn Fig. l, the line b o 79 t r e is a sinusoid curve formed byequal increments pnrellel with the line c ci, end hy increments oi'sirnple harmonic motion formed ,hy equal arcs in the circle b al e j g'it i y' cZ m n e. The line v1 o 'g is another siiiuseid, formed withSpecification of Letters iraient.

Y The manner of forming' the It will oe noted in this curve 'hithesenieelenients of silngle liorinonic ino i tion, end with shorterhorizontal increments parallel with the linec c1. i

curve, which is expleined in hooks oii ,general geometric is asfollowsz-.i circuler :irc Zi ci c, hcriiig its center c, is rst drawn;and frein-,the

`center' c is drown e straight line c ci'. The

arc of the circle is' subdividedjinto enumber of short equal uros at thepoints. o die,

drawn at right angles to from Jthe point the parallel to the line c ci.

other'points Z c f'g Zil z j Ze Z m, etca', lines line his line s drawnthe line c, c1;

Freni euch oli the are drawn parallel to 0 c1; i On 'the lineconiinencing et Z is marked e vpoint cZl, which is a horizontal unitdistant roin the line c Z. On the line commencing at e is marked a pointel, which is two units distant iii in the line c Z). @n the linecomineneingnt is marked e point y, which is three unies distant from theline c Z1.' And so, en 'i lines commencing at g. Zt e' and so on, thehorizontal linelincreasing one for erich inn crease in the length of theere freni the point Zi. Then the points 5, LZ1, areell joined, producingthe e' i f1 o p i; 3e-which is e true s' U ce die curvai-,ure increasesinostrapidly where the that the curvetnre becomes zero and changesdirection everytime the sinuedid crosses the line c 01; else that thesinnsoid curye is moving downward incst rapidly et 'the point Where ii;is changing its direction of curva- 'eir is' pnt inte simple harmoniciii-oiiien, until its denunce-rd inneren. ie

reached ce curve touches he lines Zi e ind e 72, end

fia

it clears the rear edge of the aeroplane. We

'may presume that the simple harmonic motion of the air will becontinued after the passage of the aeroplane; so that it will not cometo rest until it reaches a point represented by the letter s.

Still referring to Fig. l, the line frz, repre'- senting the line offlight, is a direct function of the intended velocity of the plane orwing and is called theelement of flight; the

line p2, by its length may indicate the back pressure of the air uponthe plane when in I 4flight; while the length of the line r2, may

indicate the lifting power of the air. Now

as the percussive force of the air varies as the square of the velocity,it follows that if the velocity of the plane is doubled the back 4pressure of the air will be increased four times, so that if the lengthof the line r2, be doubled, and the sinusoid curves of the sup-l portingsurface of the plane be stretched out 'y accordingly, a given body ofair will be twice as long in engagement Wirth the aeroplane as 1t wasbefore, while its back pressure will be )ust what 1t was at the slowerspeed, although its supporting power will be twice great. l/Vhat theactual length of the line representing the element of flight should befor any one velocity has not yet been accurately' determined.

The horizontal units of increment correspond to the velocity of thewing. So it bevlcomes evident that, for a more rapidly mov-y .ingaeroplane, the horizontal increments will become longer, and for a moreslowly moving aeroplane, the horizontal increments will become shorter.f

In Fig. 2 are represented, in longitudinal vertical section, anddiagrammatically, three aeroplanes or wings intended for slow, iney diumand rapid iight, the wings being considered from left to right. Thisview eX- hibits the differences of curvature between the several wings,and at the same time illustrates the fact that each wing, althoughdiffering from each other one, is of a true sinusoid curve inlongitudinal cross section. f f5 represents in plan view, diagrammatically, and superposed for the sake of comparison, a series of fiveaeroplanes intended for different degrees of speed in flight, the oneintended for slowest speed being represented on top, and that for fastfproximately-7 a wing formed for a speed of fty miles per hour (twodegrees) will have two and one-half times as much fore-andaft as one forforty miles (ve degrees).

Professor Langleys complete deductions, for a four-inch pla-ne,fore-andyaft, are approximately as follows:

Miles per hour. Degrees of elevation Referring to Fig. l, let the anglec r p equal the angle of attack for the intended speed. Forconveniencethe present calculations will be formed on that part of thetangent c b would be 72 inches multiplied.

by .03492, which equals 2.51424 inches, and the curve b al e f o may bedeveloped as previously explained. It is evident that the curve b o p rshown in Fig. 1 is intended for a slower speed than 50 miles per hour,as the angle c 7' p is about 27, which would correspond with a speed ofsomething less than 20 miles per hour. If a speed of 40 miles per hourbe assumed the angle c 7' p will be 5, and the tangent of this angle is.08749. Ifvthe line c o be shortened in proportion to the reduction ofspeed it will be the fore-and-aft dimensions, in inches, of an aeroplaneintended for this speed, 40 miles per hour. Then the line c b will be57.6 inches multiplied by .08749, which equals 5.039 inches. It isthought that, owing to the superior efciency of aeroplanes of the typedescribed in this case, probably a somewhat smaller angle of attack willbe found sufficient` and that this will be effected by lengthening theline' c o, giving greater support for the same speed of flight. Now, ifeach horizontal increment be taken as equal to four inches; and sincethe number of circular increments in onequarter phase equals ninetydegrees divided by the angle of pitch,-it follows that the correctfore-and-aft of wings adapted to certain speeds will be about asfollows:

Miles per liour..'..... 24

It is evident that, according to the above rule, all wings willhaxgegithe same absolute shape, larger or smaller. It is probable thatexperience will show that the horizontal inclement should preferablybear a dilferent 'ratio to the circula-rV increment than 1:1. ln

' curate observations and calculations, Will no doubt require more orless modification of the above results; but, as given, theyare the lbestnoW obtainable, Aand the principles herein enunciated v'vill foreverremain the same. l `The structureV of the Wing maybe any suitable onedesired. Lightness and strength will, ofcourse, be aimed at under allcircumlstances. The Wing may be of substantially uniform Widththroughout its fore-andaft, and lof substantially uniform thickness, and

-`strengthened and maintained in desired curved .shape by any meansdesired.

What I claim is: ,Y l. A Wing for aerial dynamics and other purposes,comprising a body Whose foreand-aft is formed to correspond to asinusoid curve, the point of greatest curvature being at the front edgeof said body and the point of zero curvature being at the rear edge,thus comprising one-fourth phase of the said curve.

2. A Wing for use in aerial dynamics the acting surface of which is sodeveloped that its lines in the direction of its intended inotion ofprogression .are sinusoid curves, the linear elements of which curvesare 4propo:- tional to the velocity at which the Wing is intended toprogress being longer for rapid and shorter for slow flight.

3. A Wing for use in aerial dynamics comprising a body with a surfacethat acts on the air through which the wing progresses, such surfacehaving foresand-aft dimensions formed to `correspond with substantiallyone-fourth phases of true sinusoid curves.

4. A Wing for aeroplanes, the acting surface of which is developed sothat its lines in the direction of its intended motion of progressionare sinusoid curves, the linear elements of Which `curves areapproximate functions of the velocity of progression which the said Wingis intended to maintain and are each approximately equal to one-fourthphase of the said sinusoid curves.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing Witnesses.

RUT-ER WLLIAM SPRNGER.

Witnesses:

WiLLLeMA W. ADAMS., WALTER H. BnsrRoM.

